Answer:
n = 4
Explanation:
As we know that the energy of the photon for a given wavelength is given as
[tex]E = \frac{hc}{\lambda}[/tex]
so it is given as
[tex]E_1 = \frac{1240}{1870}[/tex]
[tex]E_1 = 0.66 eV[/tex]
similarly for other photon we have
[tex]E_2 = \frac{1240}{102.5}[/tex]
[tex]E_2 = 12.09 eV[/tex]
So we have
[tex]E = E_1 + E_2[/tex]
[tex]E = 12.09 + 0.66 [/tex]
[tex]E = 12.75[/tex]
so we have
[tex]E = \frac{13.6}{n^2}[/tex]
[tex]12.75 = 13.6(1 - \frac{1}{n^2})[/tex]
[tex]n = 4[/tex]